Start function in Game interface

engine/engine.go

@@ -1,7 +1,10 @@
 package engine
 
 import (
+	"runtime"
+
 	"github.com/bloeys/nmage/input"
+	"github.com/bloeys/nmage/renderer"
 	"github.com/bloeys/nmage/timing"
 	"github.com/go-gl/gl/v4.1-core/gl"
 	"github.com/inkyblackness/imgui-go/v4"
@@ -9,8 +12,10 @@ import (
 )
 
 type Window struct {
-	SDLWin *sdl.Window
-	GlCtx  sdl.GLContext
+	SDLWin         *sdl.Window
+	GlCtx          sdl.GLContext
+	EventCallbacks []func(sdl.Event)
+	Rend           renderer.Render
 }
 
 func (w *Window) handleInputs() {
@@ -20,6 +25,12 @@ func (w *Window) handleInputs() {
 
 	for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
 
+		//Fire callbacks
+		for i := 0; i < len(w.EventCallbacks); i++ {
+			w.EventCallbacks[i](event)
+		}
+
+		//Internal processing
 		switch e := event.(type) {
 
 		case *sdl.MouseWheelEvent:
@@ -85,6 +96,7 @@ func (w *Window) Destroy() error {
 
 func Init() error {
 
+	runtime.LockOSThread()
 	timing.Init()
 	err := initSDL()
 
@@ -117,15 +129,15 @@ func initSDL() error {
 	return nil
 }
 
-func CreateOpenGLWindow(title string, x, y, width, height int32, flags WindowFlags) (*Window, error) {
-	return createWindow(title, x, y, width, height, WindowFlags_OPENGL|flags)
+func CreateOpenGLWindow(title string, x, y, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
+	return createWindow(title, x, y, width, height, WindowFlags_OPENGL|flags, rend)
 }
 
-func CreateOpenGLWindowCentered(title string, width, height int32, flags WindowFlags) (*Window, error) {
-	return createWindow(title, -1, -1, width, height, WindowFlags_OPENGL|flags)
+func CreateOpenGLWindowCentered(title string, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
+	return createWindow(title, -1, -1, width, height, WindowFlags_OPENGL|flags, rend)
 }
 
-func createWindow(title string, x, y, width, height int32, flags WindowFlags) (*Window, error) {
+func createWindow(title string, x, y, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
 
 	if x == -1 && y == -1 {
 		x = sdl.WINDOWPOS_CENTERED
@@ -136,7 +148,11 @@ func createWindow(title string, x, y, width, height int32, flags WindowFlags) (*
 	if err != nil {
 		return nil, err
 	}
-	win := &Window{SDLWin: sdlWin}
+	win := &Window{
+		SDLWin:         sdlWin,
+		EventCallbacks: make([]func(sdl.Event), 0),
+		Rend:           rend,
+	}
 
 	win.GlCtx, err = sdlWin.GLCreateContext()
 	if err != nil {

engine/game.go

@@ -8,6 +8,7 @@ import (
 
 type Game interface {
 	Init()
+	Start()
 
 	FrameStart()
 	Update()
@@ -23,12 +24,21 @@ type Game interface {
 
 func Run(g Game) {
 
-	g.Init()
-
 	w := g.GetWindow()
 	ui := g.GetImGUI()
+
+	g.Init()
+
+	//Simulate an imgui frame during init so any imgui calls are allowed within init
+	tempWidth, tempHeight := w.SDLWin.GetSize()
+	tempFBWidth, tempFBHeight := w.SDLWin.GLGetDrawableSize()
+	ui.FrameStart(float32(tempWidth), float32(tempHeight))
+	g.Start()
+	ui.Render(float32(tempWidth), float32(tempHeight), tempFBWidth, tempFBHeight)
+
 	for g.ShouldRun() {
 
+		//PERF: Cache these
 		width, height := w.SDLWin.GetSize()
 		fbWidth, fbHeight := w.SDLWin.GLGetDrawableSize()
 
@@ -46,6 +56,7 @@ func Run(g Game) {
 		w.SDLWin.GLSwap()
 
 		g.FrameEnd()
+		w.Rend.FrameEnd()
 		timing.FrameEnded()
 	}
 

main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"fmt"
-	"runtime"
 
 	"github.com/bloeys/assimp-go/asig"
 	"github.com/bloeys/gglm/gglm"
@@ -12,24 +11,28 @@ import (
 	"github.com/bloeys/nmage/logging"
 	"github.com/bloeys/nmage/materials"
 	"github.com/bloeys/nmage/meshes"
+	"github.com/bloeys/nmage/renderer/rend3dgl"
 	"github.com/bloeys/nmage/timing"
 	nmageimgui "github.com/bloeys/nmage/ui/imgui"
-	"github.com/go-gl/gl/v4.1-core/gl"
 	"github.com/inkyblackness/imgui-go/v4"
 	"github.com/veandco/go-sdl2/sdl"
 )
 
 //TODO: Tasks:
-//Proper rendering setup
-//Entities and components
-//Camera class
-//Audio
-//Flesh out the material system
+// Build simple game
+// Integrate physx
+// Entities and components
+// Camera class
 
 //Low Priority:
+// Renderer batching
+// Scene graph
+// Separate engine loop from rendering loop? or leave it to the user?
 // Abstract keys enum away from sdl
-// Abstract UI
 // Proper Asset loading
+// Audio
+// Frustum culling
+// Material system editor with fields automatically extracted from the shader
 
 var (
 	isRunning bool = true
@@ -70,14 +73,9 @@ func (g *OurGame) Init() {
 	if err != nil {
 		logging.ErrLog.Fatalln("Failed to load texture. Err: ", err)
 	}
-	cubeMesh.AddTexture(tex)
 
-	//Set mesh textures on material
-	for _, v := range cubeMesh.TextureIDs {
-		simpleMat.AddTextureID(v)
-	}
-
-	//Enable vertex attributes
+	//Configure material
+	simpleMat.DiffuseTex = tex.TexID
 	simpleMat.SetAttribute(cubeMesh.Buf)
 
 	//Movement, scale and rotation
@@ -100,6 +98,9 @@ func (g *OurGame) Init() {
 	simpleMat.SetUnifVec3("lightColor1", lightColor1)
 }
 
+func (g *OurGame) Start() {
+}
+
 func (g *OurGame) FrameStart() {
 }
 
@@ -149,42 +150,23 @@ func (g *OurGame) Update() {
 	imgui.DragFloat3("Cam Pos", &camPos.Data)
 }
 
-var dtAccum float32 = 0
-var lastElapsedTime uint64 = 0
-var framesSinceLastFPSUpdate uint = 0
-
 func (g *OurGame) Render() {
 
-	simpleMat.Bind()
-	cubeMesh.Buf.Bind()
 	tempModelMat := modelMat.Clone()
 
 	rowSize := 100
 	for y := 0; y < rowSize; y++ {
 		for x := 0; x < rowSize; x++ {
-			simpleMat.SetUnifMat4("modelMat", &tempModelMat.Translate(gglm.NewVec3(-1, 0, 0)).Mat4)
-			gl.DrawElements(gl.TRIANGLES, cubeMesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
+			tempModelMat.Translate(gglm.NewVec3(-1, 0, 0))
+			window.Rend.Draw(cubeMesh, tempModelMat, simpleMat)
 		}
-		simpleMat.SetUnifMat4("modelMat", &tempModelMat.Translate(gglm.NewVec3(float32(rowSize), -1, 0)).Mat4)
-	}
-	simpleMat.SetUnifMat4("modelMat", &modelMat.Mat4)
-
-	dtAccum += timing.DT()
-	framesSinceLastFPSUpdate++
-	if timing.ElapsedTime() > lastElapsedTime {
-
-		avgDT := dtAccum / float32(framesSinceLastFPSUpdate)
-		g.GetWindow().SDLWin.SetTitle(fmt.Sprint("nMage (", 1/avgDT, " fps)"))
-
-		dtAccum = 0
-		framesSinceLastFPSUpdate = 0
+		tempModelMat.Translate(gglm.NewVec3(float32(rowSize), -1, 0))
 	}
 
-	lastElapsedTime = timing.ElapsedTime()
+	g.GetWindow().SDLWin.SetTitle(fmt.Sprint("nMage (", timing.GetAvgFPS(), " fps)"))
 }
 
 func (g *OurGame) FrameEnd() {
-
 }
 
 func (g *OurGame) ShouldRun() bool {
@@ -205,8 +187,6 @@ func (g *OurGame) Deinit() {
 
 func main() {
 
-	runtime.LockOSThread()
-
 	//Init engine
 	err := engine.Init()
 	if err != nil {
@@ -214,7 +194,7 @@ func main() {
 	}
 
 	//Create window
-	window, err = engine.CreateOpenGLWindowCentered("nMage", 1280, 720, engine.WindowFlags_RESIZABLE)
+	window, err = engine.CreateOpenGLWindowCentered("nMage", 1280, 720, engine.WindowFlags_RESIZABLE, rend3dgl.NewRend3DGL())
 	if err != nil {
 		logging.ErrLog.Fatalln("Failed to create window. Err: ", err)
 	}

materials/material.go

@@ -12,7 +12,8 @@ import (
 type Material struct {
 	Name       string
 	ShaderProg shaders.ShaderProgram
-	TexIDs     []uint32
+
+	DiffuseTex uint32
 
 	UnifLocs   map[string]int32
 	AttribLocs map[string]int32
@@ -21,19 +22,17 @@ type Material struct {
 func (m *Material) Bind() {
 
 	gl.UseProgram(m.ShaderProg.ID)
-	for i, v := range m.TexIDs {
-		gl.ActiveTexture(gl.TEXTURE0 + uint32(i))
-		gl.BindTexture(gl.TEXTURE_2D, v)
-	}
+
+	gl.ActiveTexture(gl.TEXTURE0)
+	gl.BindTexture(gl.TEXTURE_2D, m.DiffuseTex)
 }
 
 func (m *Material) UnBind() {
-
 	gl.UseProgram(0)
-	for i := range m.TexIDs {
-		gl.ActiveTexture(gl.TEXTURE0 + uint32(i))
-		gl.BindTexture(gl.TEXTURE_2D, 0)
-	}
+
+	//TODO: Should we unbind textures here? Are these two lines needed?
+	// gl.ActiveTexture(gl.TEXTURE0)
+	// gl.BindTexture(gl.TEXTURE_2D, 0)
 }
 
 func (m *Material) GetAttribLoc(attribName string) int32 {
@@ -79,10 +78,6 @@ func (m *Material) SetAttribute(bufObj buffers.Buffer) {
 	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
 }
 
-func (m *Material) AddTextureID(texID uint32) {
-	m.TexIDs = append(m.TexIDs, texID)
-}
-
 func (m *Material) EnableAttribute(attribName string) {
 	gl.EnableVertexAttribArray(uint32(m.GetAttribLoc(attribName)))
 }

meshes/mesh.go

@@ -7,18 +7,12 @@ import (
 	"github.com/bloeys/assimp-go/asig"
 	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/nmage/asserts"
-	"github.com/bloeys/nmage/assets"
 	"github.com/bloeys/nmage/buffers"
 )
 
 type Mesh struct {
-	Name       string
-	TextureIDs []uint32
-	Buf        buffers.Buffer
-}
-
-func (m *Mesh) AddTexture(tex assets.Texture) {
-	m.TextureIDs = append(m.TextureIDs, tex.TexID)
+	Name string
+	Buf  buffers.Buffer
 }
 
 func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh, error) {

renderer/rend3dgl/rend3dgl.go

@@ -0,0 +1,41 @@
+package rend3dgl
+
+import (
+	"github.com/bloeys/gglm/gglm"
+	"github.com/bloeys/nmage/materials"
+	"github.com/bloeys/nmage/meshes"
+	"github.com/bloeys/nmage/renderer"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
+
+var _ renderer.Render = &Rend3DGL{}
+
+type Rend3DGL struct {
+	BoundMesh *meshes.Mesh
+	BoundMat  *materials.Material
+}
+
+func (r3d *Rend3DGL) Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material) {
+
+	if mesh != r3d.BoundMesh {
+		mesh.Buf.Bind()
+		r3d.BoundMesh = mesh
+	}
+
+	if mat != r3d.BoundMat {
+		mat.Bind()
+		r3d.BoundMat = mat
+	}
+
+	mat.SetUnifMat4("modelMat", &trMat.Mat4)
+	gl.DrawElements(gl.TRIANGLES, mesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
+}
+
+func (r3d *Rend3DGL) FrameEnd() {
+	r3d.BoundMesh = nil
+	r3d.BoundMat = nil
+}
+
+func NewRend3DGL() *Rend3DGL {
+	return &Rend3DGL{}
+}

renderer/renderer.go

@@ -0,0 +1,12 @@
+package renderer
+
+import (
+	"github.com/bloeys/gglm/gglm"
+	"github.com/bloeys/nmage/materials"
+	"github.com/bloeys/nmage/meshes"
+)
+
+type Render interface {
+	Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material)
+	FrameEnd()
+}

timing/timing.go

@@ -1,11 +1,19 @@
 package timing
 
-import "time"
+import (
+	"time"
+)
 
 var (
 	dt         float32 = 0.01
 	frameStart time.Time
 	startTime  time.Time
+
+	//fps calculator vars
+	dtAccum                  float32 = 1
+	lastElapsedTime          uint64  = 0
+	framesSinceLastFPSUpdate uint    = 0
+	avgFps                   float32 = 1
 )
 
 func Init() {
@@ -13,11 +21,30 @@ func Init() {
 }
 
 func FrameStarted() {
+
 	frameStart = time.Now()
+
+	//fps stuff
+	dtAccum += dt
+	framesSinceLastFPSUpdate++
+	et := ElapsedTime()
+	if et > lastElapsedTime {
+		avgDT := dtAccum / float32(framesSinceLastFPSUpdate)
+		avgFps = 1 / avgDT
+
+		dtAccum = 0
+		framesSinceLastFPSUpdate = 0
+	}
+	lastElapsedTime = et
 }
 
 func FrameEnded() {
+
+	//Calculate new dt
 	dt = float32(time.Since(frameStart).Seconds())
+	if dt == 0 {
+		dt = float32(time.Microsecond)
+	}
 }
 
 //DT is frame deltatime in seconds
@@ -25,6 +52,11 @@ func DT() float32 {
 	return dt
 }
 
+//GetAvgFPS returns the fps averaged over 1 second
+func GetAvgFPS() float32 {
+	return avgFps
+}
+
 //ElapsedTime is time since game start
 func ElapsedTime() uint64 {
 	return uint64(time.Since(startTime).Seconds())

ui/imgui/imgui.go

@@ -14,10 +14,10 @@ type ImguiInfo struct {
 	ImCtx *imgui.Context
 
 	Mat        *materials.Material
-	vaoID      uint32
-	vboID      uint32
-	indexBufID uint32
-	texID      uint32
+	VaoID      uint32
+	VboID      uint32
+	IndexBufID uint32
+	TexID      uint32
 }
 
 func (i *ImguiInfo) FrameStart(winWidth, winHeight float32) {
@@ -28,15 +28,7 @@ func (i *ImguiInfo) FrameStart(winWidth, winHeight float32) {
 
 	imIO := imgui.CurrentIO()
 	imIO.SetDisplaySize(imgui.Vec2{X: float32(winWidth), Y: float32(winHeight)})
-
-	// Setup time step (we don't use SDL_GetTicks() because it is using millisecond resolution)
-	frequency := sdl.GetPerformanceFrequency()
-	currentTime := sdl.GetPerformanceCounter()
-	if timing.ElapsedTime() > 0 {
-		imIO.SetDeltaTime(float32(currentTime-timing.ElapsedTime()) / float32(frequency))
-	} else {
-		imIO.SetDeltaTime(1.0 / 60.0)
-	}
+	imIO.SetDeltaTime(timing.DT())
 
 	imgui.NewFrame()
 }
@@ -85,8 +77,8 @@ func (i *ImguiInfo) Render(winWidth, winHeight float32, fbWidth, fbHeight int32)
 	// Recreate the VAO every time
 	// (This is to easily allow multiple GL contexts. VAO are not shared among GL contexts, and
 	// we don't track creation/deletion of windows so we don't have an obvious key to use to cache them.)
-	gl.BindVertexArray(i.vaoID)
-	gl.BindBuffer(gl.ARRAY_BUFFER, i.vboID)
+	gl.BindVertexArray(i.VaoID)
+	gl.BindBuffer(gl.ARRAY_BUFFER, i.VboID)
 
 	vertexSize, vertexOffsetPos, vertexOffsetUv, vertexOffsetCol := imgui.VertexBufferLayout()
 	i.Mat.EnableAttribute("Position")
@@ -106,11 +98,11 @@ func (i *ImguiInfo) Render(winWidth, winHeight float32, fbWidth, fbHeight int32)
 	for _, list := range drawData.CommandLists() {
 
 		vertexBuffer, vertexBufferSize := list.VertexBuffer()
-		gl.BindBuffer(gl.ARRAY_BUFFER, i.vboID)
+		gl.BindBuffer(gl.ARRAY_BUFFER, i.VboID)
 		gl.BufferData(gl.ARRAY_BUFFER, vertexBufferSize, vertexBuffer, gl.STREAM_DRAW)
 
 		indexBuffer, indexBufferSize := list.IndexBuffer()
-		gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, i.indexBufID)
+		gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, i.IndexBufID)
 		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, indexBufferSize, indexBuffer, gl.STREAM_DRAW)
 
 		for _, cmd := range list.Commands() {
@@ -118,7 +110,7 @@ func (i *ImguiInfo) Render(winWidth, winHeight float32, fbWidth, fbHeight int32)
 				cmd.CallUserCallback(list)
 			} else {
 
-				gl.BindTexture(gl.TEXTURE_2D, i.texID)
+				gl.BindTexture(gl.TEXTURE_2D, i.TexID)
 				clipRect := cmd.ClipRect()
 				gl.Scissor(int32(clipRect.X), int32(fbHeight)-int32(clipRect.W), int32(clipRect.Z-clipRect.X), int32(clipRect.W-clipRect.Y))
 
@@ -134,6 +126,30 @@ func (i *ImguiInfo) Render(winWidth, winHeight float32, fbWidth, fbHeight int32)
 	gl.Enable(gl.DEPTH_TEST)
 }
 
+func (i *ImguiInfo) AddFontTTF(fontPath string, fontSize float32, fontConfig *imgui.FontConfig, glyphRanges *imgui.GlyphRanges) imgui.Font {
+
+	fontConfigToUse := imgui.DefaultFontConfig
+	if fontConfig != nil {
+		fontConfigToUse = *fontConfig
+	}
+
+	glyphRangesToUse := imgui.EmptyGlyphRanges
+	if glyphRanges != nil {
+		glyphRangesToUse = *glyphRanges
+	}
+
+	imIO := imgui.CurrentIO()
+
+	a := imIO.Fonts()
+	f := a.AddFontFromFileTTFV(fontPath, fontSize, fontConfigToUse, glyphRangesToUse)
+	image := a.TextureDataAlpha8()
+
+	gl.BindTexture(gl.TEXTURE_2D, i.TexID)
+	gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RED, int32(image.Width), int32(image.Height), 0, gl.RED, gl.UNSIGNED_BYTE, image.Pixels)
+
+	return f
+}
+
 func NewImGUI() ImguiInfo {
 
 	imguiInfo := ImguiInfo{
@@ -144,13 +160,13 @@ func NewImGUI() ImguiInfo {
 	imIO := imgui.CurrentIO()
 	imIO.SetBackendFlags(imIO.GetBackendFlags() | imgui.BackendFlagsRendererHasVtxOffset)
 
-	gl.GenVertexArrays(1, &imguiInfo.vaoID)
-	gl.GenBuffers(1, &imguiInfo.vboID)
-	gl.GenBuffers(1, &imguiInfo.indexBufID)
-	gl.GenTextures(1, &imguiInfo.texID)
+	gl.GenVertexArrays(1, &imguiInfo.VaoID)
+	gl.GenBuffers(1, &imguiInfo.VboID)
+	gl.GenBuffers(1, &imguiInfo.IndexBufID)
+	gl.GenTextures(1, &imguiInfo.TexID)
 
 	// Upload font to gpu
-	gl.BindTexture(gl.TEXTURE_2D, imguiInfo.texID)
+	gl.BindTexture(gl.TEXTURE_2D, imguiInfo.TexID)
 	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
 	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
 	gl.PixelStorei(gl.UNPACK_ROW_LENGTH, 0)
@@ -159,7 +175,7 @@ func NewImGUI() ImguiInfo {
 	gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RED, int32(image.Width), int32(image.Height), 0, gl.RED, gl.UNSIGNED_BYTE, image.Pixels)
 
 	// Store our identifier
-	imIO.Fonts().SetTextureID(imgui.TextureID(imguiInfo.texID))
+	imIO.Fonts().SetTextureID(imgui.TextureID(imguiInfo.TexID))
 
 	//Shader attributes
 	imguiInfo.Mat.Bind()